Three-section cascade



Jan. 26, 1965 B. D. MARSELLO 3,166,924

THREE-SECTION CASCADE Filed Jan. 20, 1964 2 8 INVENTOR.

BERNARD D. MARSELLO ATTORNEY BY F/G.2.

United States Patent 3,166,924 THREE-SECTi-(BN CASCADE Bernard D. Marselio, Decatur, Ala, assignor to Monsanto Cempan a corporation of fielaware Filed Ian. 29, 1964, er. No. 338,758

1 Claim. (Qt. 68-19) This invention relates to the washing of synthetic fibers and more particularly to the Stripping and squeez ing of a tow which is comprised of synthetic fibers as it is drawn up a washer cascade.

' In the wet spinning process of making synthetic fibers, a dope which consists of a polymer or co-polymer and a solvent is extruded through spinnerettes into a coagulation bath. Filaments are formed as the coagulating fluid comes in contact with the dope, are collected, the aggregation of which comprise the tow, and then are drawn up a cascade by any suitable means. As hot water flows down the cascade, it comes in contact with the tow and removes the solvent therefrom. A current problem in the washing of filamentary tows is that the solvent in the fiber is not reduced to an acceptable level. Tows having a non-uniform, high residual solvent exhibit poor textile processing characteristics. The industry has experienced difiiculty in removing the solvent for the tow as it travels up the cascade it carries therewith an amount of wash water which forms a boundary layer around each filament. This boundary layer impedes the rinsing process for the wash water cannot efifectively circulate around the fibers due to the afiinity of the fibers for the water. The'boundary layer of wash water can be removed with varying degrees of success by -a stripping process, the stripping can be done either by sharply bending the tow or by nipping the tow. Since the tow is generally drawn up the cascade along a straight path and under tension, it cannot be bent with any effectiveness; therefore, some method of nipping must be employed. The prior art teaches stripper bars and the like which help remove the boundary layer of wash water but such devices cannot be effectively monitored and since the tow remains in the wash water, there is always a minute layer of wash water surrounding the fibers. Another disadvantage is that where tows of large denier are being washed, the fibers located in the middle of the tow are not stripped for the stripper bar does not contact the inner fibers. The boundary layer of water surrounding the inner fibers may be removed if the weight of the stripper bar is increased but in doing so the friction between the outer fibers and the bar becomes too great thereby breaking some of those fibers and damaging the rest. In view of the above where tows of large denier are being washed, the solvent is not uniformly removed from the tow. This non-uniformity creates handling problems for the fibers having a high residual solvent are notof the same quality as the remainder and cannot be packaged and sold in the same batch. Therefore, a primary object of this invention is to provide a cascade with a stripper which will effectively remove the boundary layer of wash water from all of the filaments which comprise the tow and which will permit fresh wash water to rinse the tow and remove the remaining undesirable solvent.

Another object of this invention is to provide a cascade with a stripper which may be micrometrically adjusted.

A further object of this invention is to provide a cascade with a stripper which removes the boundary layer of wash water from the tow while the tow is in a raised position relative to the cascade and the wash water therein.

Still another object of this invention is to provide a cascade with a stripper which removes the boundary layer of water from the tow and also guides and aligns the tow.

3,l5fi,24 Patented Jan. 26, 1965 Other objects and advantages of this invention will become apparent when the following etailed description is read in conjunction with the appended drawings, specifications and claims. Preferred embodiments of this invention will now be described with reference to the accompanying drawings.

FIGURE 1 is a pictorial, sectional view of the apparatus showing the micrometer adjustments in relation to the movable stripper bar, the stationary stripper bars and the cascade.

FIGURE 2 is a cross-sectional view showing the linkage between the adjustment screw and the movable stripper bar.

FIGURE 3 is a pictorial view of the socket joint showing the hole which receives the shaft of the stripper bar.

One embodiment of the present invention contemplates using a micrometrically adjusted stripper bar to impinge a filamentary tow against a plurality of stationary stripper bars. These stripper bars act to wring the tow free of wash water and remove the boundary layer of wash water therefrom by stripping. One stationary stripper bar guides the tow upwardly thereby raising it above the level of the cascade wash water and the other bars strip the tow while in that emerged state thereby more effectively removing the boundary layer of wash water therein. The tow after traversing the various stripper bars again comes into contact with the wash water and is further rinsed.

A set of clamps is respectively mounted on each wall of the cascade and is rigidly fastened thereon by any Well known means. Each clamp has an arm which extends inwardly, is parallel to the floor of the cascade and is provided with a hold being perpendicularly located therein which is threaded.

The threaded hole is adapted to receive an adjusting screw, the adjusting screw having a shaft-like body, a portion of which is threaded, a knob for facilitating the turning thereof being located at one end and spherical ball being connected to the other end by means of a stake. A linkage which joins the adjusting screw with a movable stripper bar receives the spherical ball by means of a cylindrical socket. The stripping mechanism is provided with the ball and socket arrangement in order to allow each side of the stripper to be individually adjusted for if each adjusting screw were rigidly connected to the stripper bar, both sides of the stripper bar would have to be simultaneously adjusted to prevent locking. Each end of the stripper bar is provided with a small shaft which is stationarily received by an opening in each linkage.

In order to eifectively practice this invention, the cascade is provided with a well which receives two stationary stripper bars. Those two bars are rigidly mounted in the cascade walls and extend thereacross. Since the eascade resides in an inclined plane and since the stationary stripper bars are in a plane parallel to the floor of the cascade, the forward bar is elevated relative to the rear bar. As a segment of the tow advances, it first strikes the rear stripper bar and is raised out of the cascade wash water. This segment then passes under the movable stripper bar which has been lowered into an impinging position with the tow thereby stripping the upper side of the same and forcing a portion of the wash water therefrom. The above mentioned segment after having one side stripped then passes to the forward stationary stripper bar and passes in contact thereover thereby having the other side stripped whereupon more Wash water is forced therefrom. Since this segment has been subjected to two stripping actions, it is relatively free of wash Water and the boundary layer of wash water surrounding the filaments is removed therefrom. The segment being relatively free of wash water then passes under an aligning bar which is located in the cascade. This bar guides the tow into the wash water thereby immediately pro viding for the continuation of the washing process for the tow having the boundary layer of wash water removed attracts the fresh wash water and while a new boundary layer is forming around the filaments, the undesirable solvent is further reduced.

The'invention is illustrated in connection with the accompanying drawings in which the figures are illustrative of the preferred embodiment of the invention.

A cascade 10, which is trough-shaped in design for carrying a washing fluid such as hot water 11, receives a clamp 12 on each wall 13 and 14. The clamp 12 has a groove 41 which fits over the wall 13 of the cascade It) and is secured thereon by any well-known means, such as, a set screw 4%. The clamp 12 has an arm 15 extending over the cascade 10 which has a threaded hole 16 therein. An adjusting screw 17 has a portion of its length threaded as indicated by reference numeral 18 which is threadably received by threaded hole L5. On the upper end of adjusting screw 17, a knob 19 is mounted thereon which is designed to be received by the hand and to facilitate the turning thereof. The lower end of adjusting screw 17 has extending therefrom a stake 29 which connects a spherical ball 21 tothe adjusting screw i7. A linkage 22 receives the ball 21 in a socket 23 which is a cylindrical hole having a slot 24 that extends upwardly to the surface thereof. The socket 23 and the slot 24 house the ball 21 and the stake 2%, respectively, so as to permit movement therein. Below the socket 23, a hole 25 is drilled through the linkage 22 which receives an extension 26 of the movable stripper bar 27. By having both ends of the movable stripper bar 27 rigidly mounted in a linkage, it is operable to move in a vertical path and can be positioned in contact against the tow 29 with any degree of pressure necessary.

. The other parts of this apparatus statically co-operating with the movable stripper bar 27 include a rear stripper bar 31 which is located in a well 30 and is rigidly mounted in the walls of cascade 10. This rear stripper bar 31 is positioned so as to raise the tow 29 off of the cascade floor 28 and out of the cascade wash water 11. When the movable stripper bar 27 is in a raised position, the tow 29 travels unobstructedly and free from wash water from the rear stripper bar 31 to a forward stripper bar 32 which is raised relative thereto and then passes under an aligning bar 33 which is stationarily mounted in the walls of cascade 10 and there is ire-submerged in wash water 11.

In operation, a filamentary tow 29 is pulled under tension across stationary stripper bars 31 and 32 and is raised out of the wash water 11. A movable stripper bar 27 is positioned between the stripper bars 31 and 32 and can be lowered into a contacting position therewith by means of the micrometer adjustments. Since the tow 29 is continually under elongating tension as it is pulled up the cascade 1d, the movable stripper bar 27 has only to deflect the path thereof a slight degree in order to generate the proper stripping action. Although the rear stripper bar 31 partially strips the tow 29, its main function is to raise the tow 29 from the wash water Ill. The movable stripper bar 2'] acts to strip the upper surface of the tow 29 and wring the wash water 11 therefrom and the forward stripper bar co-operates therewith by stripping the lower surface thereof and further removing the Wash water 11 therefrom. Although the filaments comprising the inner portions of the tow 29 never are actually stripped by a stripper bar, the boundary layer of wash water 11 has been virtually eliminated therefrom. The wash water 11 is removed from the tow 29 by the action of the outer fibers on the inner ones for as the path of the tow is deflected by a stripper bar, the outer filaments are tensioned relatively greater than the inner filaments thereby pressing the inner filiments against the stripper bar causing the wash water 11 to be wrung therefrom.

Many different embodiments of this invention may be made without departing from the scope and spirit thereof. Therefore, it is to be undestood that the invention is not to be limited to the specific embodiment shown and described herein, except as defined in the appended claim.

I claim:

An apparatus for continuously stripping and wringing a filamentary tow comprising:

(a) a cascade containing a washing fluid, said cascade being provided with a well,

(5) a first stripper bar stationarily mounted in said well, said stripper bar being adapted to engage and raise said tow from said washing fluid,

(c) a second stripper bar stationarily residing in said well in contact with said tow thereby wringing and stripping the same,

(d) a third stripper bar adjustably mounted on said cascade between and above said first stripper bar and said second stripper bar and being adapted to be lowered into contact with said tow for stripping and wringing the same, said third stripper bar including a set of clamps rigidly clutching the walls of said cascade, said clamps each having an arm extending over said cascade, the said arm having therein a threaded hole, an adjusting screw being provided for and being received by each threaded hole, said adjusting screw having a handle mounted at one end and a ball at the other, a linkage for each of said adjusting screws having a socket therein for receiving said ball of said adjusting screw in a pivoting engagement, said linkage also having a hole therein for rigidly receiving an extension of said stripper bar, said stripper bar connecting the linkages thereby forming a single interconnecting element, and

(e) an aligning bar rigidly mounted in said cascade for lowering said tow into contact with said washing fluid.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Canada Apr. 23, 1963 

